Meniscal tears and articular cartilage damage in the dislocated knee.

PURPOSE: Knee dislocations can cause significant damage to intra-articular knee structures, but currently there are limited data reporting articular cartilage and meniscal injuries in this setting. The purpose of this study is to (1) report the rate of concomitant intra-articular injuries at the time of multiligament reconstruction for knee dislocation, (2) determine whether the pattern of ligament injury is associated with the presence of chondral and meniscal injuries, and (3) assess the relationship between timing of surgery and incidence of chondral and meniscal injuries.
METHODS: The records of patients who sustained a knee dislocation between 1992 and 2013 were retrospectively reviewed. Patients included for further review had a PCL-based multiligament knee injury or a minimum of three disrupted ligaments, both indicative of knee dislocation. Patient demographics, ligament injury patterns, meniscal tears and chondral injuries at arthroscopy, and interval from injury to surgery were recorded. Early surgical intervention was defined as <3 months, delayed was between 3 and 12 months, and chronic was >12 months. Data analysis compared ligament injury pattern with chondral and meniscal injuries, as well as the rates of intra-articular injury by timing of surgery.
RESULTS: One-hundred and twenty-one patients (122 knees) were included (93 males, 28 females) with a median age at time of surgery of 31 years (range 15-62). Ninety-three knees (76 %) had associated chondral or meniscal injury. Sixty-seven knees (55 %) presented with meniscal tears (26 isolated medial, 27 isolated lateral, and 14 combined medial/lateral), while 52 knees (48 %) had chondral damage, most commonly in the medial compartment. Schenck classification as well as side of injury did not demonstrate consistent relationships with intra-articular injury. A higher incidence of damage to the lateral femoral condyle (20 % vs 3 %; p = 0.02), lateral tibial plateau (20 % vs 2 %; p < 0.01), and patella (40 % vs 13 %; p = 0.01) was found in the chronic group compared to the early group. The chronic group contained significantly more patients with bicompartmental and tricompartmental chondral lesions (25 % vs 6 %; p = 0.03 and 10 % vs 0 %; p = 0.02, respectively).
CONCLUSION: Meniscal tears and chondral damage occur frequently in patients with a knee dislocation. A longer interval from injury to surgical reconstruction is associated with higher rates of articular cartilage lesions, especially in multiple compartments. LEVEL OF EVIDENCE: IV.